This study investigated the potential of local radio as a source of agricultural communication in Ghana. The main thrust of the research was to investigate the levels of unaided recall and comprehension of agricultural radio messages among rural farmers. Eight experiments were conducted in eight rural communities. In all, 252 farmers were used as subjects for the experiments. The experiments investigated the effects of specific production and audience factors on unaided recall and message understanding. The survey involved the use of questionnaires to gather data through interviews with 365 farmers. Survey methodology was used to profile rural radio listeners in Ghana; and to glean insights into the sources of general and agricultural news for rural farmers, the farmers' radio listening behaviours, radio programme format preferences, and their levels of adoption of radio agricultural messages. Unaided recall and comprehension of broadcast news were found to be generally low. Two programming variables --- recaps of news items and repeat broadcasts --- demonstrated significant impact on farmers' recall and comprehension of radio agricultural messages. Item duration was found to be very potent in influencing memory recall. Younger farmers recorded significantly higher unaided recall and comprehension scores than older farmers; and farmers with higher education performed better in free recall and comprehension of broadcast messages than those with lower levels of education. The study found that radio is the most popular source of general and agricultural news to farmers. The farmers relied mostly on radio, extension agents and interpersonal communication for agricultural information. While the farmers reported that the extension agent was the most credible among all the sources of agricultural communication, they rated radio as the most reliable.